#define DEBUG_TYPE "stackcoloring"
#include "VirtRegMap.h"
+#include "llvm/Function.h"
+#include "llvm/Module.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/LiveStackAnalysis.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineLoopInfo.h"
+#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/Support/CommandLine.h"
-#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
STATISTIC(NumDead, "Number of trivially dead stack accesses eliminated");
namespace {
- class VISIBILITY_HIDDEN StackSlotColoring : public MachineFunctionPass {
+ class StackSlotColoring : public MachineFunctionPass {
bool ColorWithRegs;
LiveStacks* LS;
VirtRegMap* VRM;
MachineFunctionPass(&ID), ColorWithRegs(RegColor), NextColor(-1) {}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesCFG();
+ AU.addRequired<SlotIndexes>();
+ AU.addPreserved<SlotIndexes>();
AU.addRequired<LiveStacks>();
AU.addRequired<VirtRegMap>();
AU.addPreserved<VirtRegMap>();
private:
void InitializeSlots();
+ bool CheckForSetJmpCall(const MachineFunction &MF) const;
void ScanForSpillSlotRefs(MachineFunction &MF);
bool OverlapWithAssignments(LiveInterval *li, int Color) const;
int ColorSlot(LiveInterval *li);
};
}
+/// CheckForSetJmpCall - Return true if there's a call to setjmp/sigsetjmp in
+/// this function.
+bool StackSlotColoring::CheckForSetJmpCall(const MachineFunction &MF) const {
+ const Function *F = MF.getFunction();
+ const Module *M = F->getParent();
+ const Function *SetJmp = M->getFunction("setjmp");
+ const Function *SigSetJmp = M->getFunction("sigsetjmp");
+
+ if (!SetJmp && !SigSetJmp)
+ return false;
+
+ if (SetJmp && !SetJmp->use_empty())
+ for (Value::const_use_iterator
+ I = SetJmp->use_begin(), E = SetJmp->use_end(); I != E; ++I)
+ if (const CallInst *CI = dyn_cast<CallInst>(I))
+ if (CI->getParent()->getParent() == F)
+ return true;
+
+ if (SigSetJmp && !SigSetJmp->use_empty())
+ for (Value::const_use_iterator
+ I = SigSetJmp->use_begin(), E = SigSetJmp->use_end(); I != E; ++I)
+ if (const CallInst *CI = dyn_cast<CallInst>(I))
+ if (CI->getParent()->getParent() == F)
+ return true;
+
+ return false;
+}
+
/// ScanForSpillSlotRefs - Scan all the machine instructions for spill slot
/// references and update spill slot weights.
void StackSlotColoring::ScanForSpillSlotRefs(MachineFunction &MF) {
if (!LS->hasInterval(FI))
continue;
LiveInterval &li = LS->getInterval(FI);
- li.weight += LiveIntervals::getSpillWeight(false, true, loopDepth);
+ if (!MI->isDebugValue())
+ li.weight += LiveIntervals::getSpillWeight(false, true, loopDepth);
SSRefs[FI].push_back(MI);
}
}
Assignments.resize(LastFI);
// Gather all spill slots into a list.
- DOUT << "Spill slot intervals:\n";
+ DEBUG(dbgs() << "Spill slot intervals:\n");
for (LiveStacks::iterator i = LS->begin(), e = LS->end(); i != e; ++i) {
LiveInterval &li = i->second;
DEBUG(li.dump());
OrigSizes[FI] = MFI->getObjectSize(FI);
AllColors.set(FI);
}
- DOUT << '\n';
+ DEBUG(dbgs() << '\n');
// Sort them by weight.
std::stable_sort(SSIntervals.begin(), SSIntervals.end(), IntervalSorter());
return false;
bool Changed = false;
- DOUT << "Assigning unused registers to spill slots:\n";
+ DEBUG(dbgs() << "Assigning unused registers to spill slots:\n");
for (unsigned i = 0, e = SSIntervals.size(); i != e; ++i) {
LiveInterval *li = SSIntervals[i];
int SS = li->getStackSlotIndex();
AllColored = false;
continue;
} else {
- DOUT << "Assigning fi#" << RSS << " to " << TRI->getName(Reg) << '\n';
+ DEBUG(dbgs() << "Assigning fi#" << RSS << " to "
+ << TRI->getName(Reg) << '\n');
ColoredRegs.push_back(Reg);
SlotMapping[RSS] = Reg;
SlotIsReg.set(RSS);
++NumEliminated;
}
}
- DOUT << '\n';
+ DEBUG(dbgs() << '\n');
return Changed;
}
// Record the assignment.
Assignments[Color].push_back(li);
int FI = li->getStackSlotIndex();
- DOUT << "Assigning fi#" << FI << " to fi#" << Color << "\n";
+ DEBUG(dbgs() << "Assigning fi#" << FI << " to fi#" << Color << "\n");
// Change size and alignment of the allocated slot. If there are multiple
// objects sharing the same slot, then make sure the size and alignment
BitVector SlotIsReg(NumObjs);
BitVector UsedColors(NumObjs);
- DOUT << "Color spill slot intervals:\n";
+ DEBUG(dbgs() << "Color spill slot intervals:\n");
bool Changed = false;
for (unsigned i = 0, e = SSIntervals.size(); i != e; ++i) {
LiveInterval *li = SSIntervals[i];
Changed |= (SS != NewSS);
}
- DOUT << "\nSpill slots after coloring:\n";
+ DEBUG(dbgs() << "\nSpill slots after coloring:\n");
for (unsigned i = 0, e = SSIntervals.size(); i != e; ++i) {
LiveInterval *li = SSIntervals[i];
int SS = li->getStackSlotIndex();
#ifndef NDEBUG
for (unsigned i = 0, e = SSIntervals.size(); i != e; ++i)
DEBUG(SSIntervals[i]->dump());
- DOUT << '\n';
+ DEBUG(dbgs() << '\n');
#endif
// Can we "color" a stack slot with a unused register?
// Delete unused stack slots.
while (NextColor != -1) {
- DOUT << "Removing unused stack object fi#" << NextColor << "\n";
+ DEBUG(dbgs() << "Removing unused stack object fi#" << NextColor << "\n");
MFI->RemoveStackObject(NextColor);
NextColor = AllColors.find_next(NextColor);
}
/// to old frame index with new one.
void StackSlotColoring::RewriteInstruction(MachineInstr *MI, int OldFI,
int NewFI, MachineFunction &MF) {
+ // Update the operands.
for (unsigned i = 0, ee = MI->getNumOperands(); i != ee; ++i) {
MachineOperand &MO = MI->getOperand(i);
if (!MO.isFI())
MO.setIndex(NewFI);
}
- // Update the MachineMemOperand for the new memory location.
- // FIXME: We need a better method of managing these too.
- SmallVector<MachineMemOperand, 2> MMOs(MI->memoperands_begin(),
- MI->memoperands_end());
- MI->clearMemOperands(MF);
+ // Update the memory references. This changes the MachineMemOperands
+ // directly. They may be in use by multiple instructions, however all
+ // instructions using OldFI are being rewritten to use NewFI.
const Value *OldSV = PseudoSourceValue::getFixedStack(OldFI);
- for (unsigned i = 0, ee = MMOs.size(); i != ee; ++i) {
- if (MMOs[i].getValue() != OldSV)
- MI->addMemOperand(MF, MMOs[i]);
- else {
- MachineMemOperand MMO(PseudoSourceValue::getFixedStack(NewFI),
- MMOs[i].getFlags(), MMOs[i].getOffset(),
- MMOs[i].getSize(), MMOs[i].getAlignment());
- MI->addMemOperand(MF, MMO);
- }
- }
+ const Value *NewSV = PseudoSourceValue::getFixedStack(NewFI);
+ for (MachineInstr::mmo_iterator I = MI->memoperands_begin(),
+ E = MI->memoperands_end(); I != E; ++I)
+ if ((*I)->getValue() == OldSV)
+ (*I)->setValue(NewSV);
}
/// PropagateBackward - Traverse backward and look for the definition of
// Abort the use is actually a sub-register def. We don't have enough
// information to figure out if it is really legal.
- if (MO.getSubReg() ||
- TID.getOpcode() == TargetInstrInfo::EXTRACT_SUBREG ||
- TID.getOpcode() == TargetInstrInfo::INSERT_SUBREG ||
- TID.getOpcode() == TargetInstrInfo::SUBREG_TO_REG)
+ if (MO.getSubReg() || MII->isExtractSubreg() ||
+ MII->isInsertSubreg() || MII->isSubregToReg())
return false;
const TargetRegisterClass *RC = TID.OpInfo[i].getRegClass(TRI);
SmallVector<MachineOperand*, 4> Uses;
while (++MII != MBB->end()) {
- bool FoundUse = false;
bool FoundKill = false;
const TargetInstrDesc &TID = MII->getDesc();
for (unsigned i = 0, e = MII->getNumOperands(); i != e; ++i) {
// Abort the use is actually a sub-register use. We don't have enough
// information to figure out if it is really legal.
- if (MO.getSubReg() ||
- TID.getOpcode() == TargetInstrInfo::EXTRACT_SUBREG)
+ if (MO.getSubReg() || MII->isExtractSubreg())
return false;
const TargetRegisterClass *RC = TID.OpInfo[i].getRegClass(TRI);
if (RC && !RC->contains(NewReg))
return false;
- FoundUse = true;
if (MO.isKill())
FoundKill = true;
MachineBasicBlock *MBB = MI->getParent();
if (unsigned DstReg = TII->isLoadFromStackSlot(MI, OldFI)) {
if (PropagateForward(MI, MBB, DstReg, Reg)) {
- DOUT << "Eliminated load: ";
+ DEBUG(dbgs() << "Eliminated load: ");
DEBUG(MI->dump());
++NumLoadElim;
} else {
- TII->copyRegToReg(*MBB, MI, DstReg, Reg, RC, RC);
+ TII->copyRegToReg(*MBB, MI, DstReg, Reg, RC, RC,
+ MI->getDebugLoc());
++NumRegRepl;
}
}
} else if (unsigned SrcReg = TII->isStoreToStackSlot(MI, OldFI)) {
if (MI->killsRegister(SrcReg) && PropagateBackward(MI, MBB, SrcReg, Reg)) {
- DOUT << "Eliminated store: ";
+ DEBUG(dbgs() << "Eliminated store: ");
DEBUG(MI->dump());
++NumStoreElim;
} else {
- TII->copyRegToReg(*MBB, MI, Reg, SrcReg, RC, RC);
+ TII->copyRegToReg(*MBB, MI, Reg, SrcReg, RC, RC,
+ MI->getDebugLoc());
++NumRegRepl;
}
if (DCELimit != -1 && (int)NumDead >= DCELimit)
break;
- MachineBasicBlock::iterator NextMI = next(I);
+ MachineBasicBlock::iterator NextMI = llvm::next(I);
if (NextMI == MBB->end()) continue;
int FirstSS, SecondSS;
bool StackSlotColoring::runOnMachineFunction(MachineFunction &MF) {
- DOUT << "********** Stack Slot Coloring **********\n";
+ DEBUG({
+ dbgs() << "********** Stack Slot Coloring **********\n"
+ << "********** Function: "
+ << MF.getFunction()->getName() << '\n';
+ });
MFI = MF.getFrameInfo();
MRI = &MF.getRegInfo();
return false;
}
+ // If there are calls to setjmp or sigsetjmp, don't perform stack slot
+ // coloring. The stack could be modified before the longjmp is executed,
+ // resulting in the wrong value being used afterwards. (See
+ // <rdar://problem/8007500>.)
+ //
+ // FIXME: This goes beyond the setjmp/sigsetjmp functions. Ideally, we should
+ // check for the GCC "returns twice" attribute.
+ if (CheckForSetJmpCall(MF))
+ return false;
+
// Gather spill slot references
ScanForSpillSlotRefs(MF);
InitializeSlots();
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